Microbial population and functional dynamics associated with surface potential and carbon metabolism
Microbial population and functional dynamics associated with surface potential and carbon metabolism
复制标题
DOI：
10.1038/ismej.2013.217
复制
发表时间：
2014-05-01
期刊：
影响因子：
11
通讯作者：
Bretschger, Orianna
中科院分区：
文献类型：
--
作者：
Ishii, Shun'ichi;Suzuki, Shino;Bretschger, Orianna
微生物胞外电子转移（EET）是在各种缺氧环境中发生的金属还原的重要反应。然而，由于电子供体和固相受体的组成和浓度的变化，准确表征EET活性微生物群落和每个成员对EET反应的贡献是具有挑战性的。在这里，我们使用生物电化学系统系统地评估了碳源和表面氧化还原电位对EET活性微生物群落发育、代谢网络和总体电子转移速率的协同作用。结果表明，更快的生物催化速率下观察到的正电性电极表面电位的条件下，和脂肪酸进料的条件下。时间16S rRNA为基础的微生物群落分析表明，Geophysicum类型是高度多样的，显然依赖于表面电位。著名的产电微生物隶属于Geelium metallireducens分支与较低的表面电位和较少的电流产生，而Geelium地下分支1和2与较高的表面电位和较大的电流产生。在特定的表面电位下，还观察到特定的发酵底物类型和Gesterol类型之间的关联。当糖存在时，Tolumonas和气单胞菌的类型优先与较低的表面电位，而乳球菌的类型被认为是密切相关的Gebulococcus地下分支1和2的类型在较高的表面电位条件下。总的来说，这些结果表明，表面电位提供了一个强大的选择压力，在物种和菌株的水平，为固体表面发酵剂和发酵微生物在整个EET活性社区的发展。
Microbial extracellular electron transfer (EET) to solid surfaces is an important reaction for metal reduction occurring in various anoxic environments. However, it is challenging to accurately characterize EET-active microbial communities and each member's contribution to EET reactions because of changes in composition and concentrations of electron donors and solid-phase acceptors. Here, we used bioelectrochemical systems to systematically evaluate the synergistic effects of carbon source and surface redox potential on EET-active microbial community development, metabolic networks and overall electron transfer rates. The results indicate that faster biocatalytic rates were observed under electropositive electrode surface potential conditions, and under fatty acid-fed conditions. Temporal 16S rRNA-based microbial community analyses showed that Geobacter phylotypes were highly diverse and apparently dependent on surface potentials. The well-known electrogenic microbes affiliated with the Geobacter metallireducens clade were associated with lower surface potentials and less current generation, whereas Geobacter subsurface clades 1 and 2 were associated with higher surface potentials and greater current generation. An association was also observed between specific fermentative phylotypes and Geobacter phylotypes at specific surface potentials. When sugars were present, Tolumonas and Aeromonas phylotypes were preferentially associated with lower surface potentials, whereas Lactococcus phylotypes were found to be closely associated with Geobacter subsurface clades 1 and 2 phylotypes under higher surface potential conditions. Collectively, these results suggest that surface potentials provide a strong selective pressure, at the species and strain level, for both solid surface respirators and fermentative microbes throughout the EET-active community development.